The present invention relates to a system for influencing the speed of a motor vehicle. Such control systems are increasingly used under the description ACC (Autonomous/Adaptive Cruise Control) in motor vehicles, in particular top-of-the-range and upper-mid-range class models.
Devices are known that regulate the driving speed of a motor vehicle, in which the driver can preset a desired speed and the driving speed of the motor vehicle can be brought to and maintained at this target speed by means of a speed regulator as long as this device is activated. However, with this system there is no monitoring of the driving speed of a vehicle in front. The driver therefore has to act when his vehicle approaches the vehicle in front. Likewise, the driver can however also correspondingly increase the speed of his vehicle if the speed of the vehicle in front increases.
A device that takes over from the driver the task of monitoring the distance to the vehicle in front and that matches the speed of the driver's vehicle to the speed of a vehicle in front is described for example in EP-A-0 612 641.
In order to broaden successfully the use of such ACC systems, a safer and more reliable operation of this system is necessary, which also results in better driving comfort and thus in an improved acceptability when driving. In particular the invention is concerned with the problem of making the vehicle's driving behavior more reliable